(a) Field of the Invention
The present invention relates to a structure for attaching a dust collection electrode of a wet electric dust collector. In particular, the present invention relates to a structure for attaching dust collection electrodes of a wet electric dust collection apparatus that prevents the corrosion in a low pH environment by the cleaning by cleaning water for removing dust or the like collected and attached as the dust collector operates.
(b) Description of the Related Art
An electric dust collector is designed so that a discharge electrode and a dust collection electrode are alternately arranged so that exhaust gas passes therebetween to electrically-charge microparticles (dust) in the exhaust gas by electric discharge to allow the dust to be trapped by the dust collection electrode. As the dust collector operates, dust or the like is collected and attached around the dust collection electrode of the dust collector. When sulfur components are mixed in exhaust gas passing through the dust collector, a risk is caused where these sulfur components turn into sulfur oxides that are attached to the dust collector to corrode the dust collector. Generally, the trapped dust or the like is removed by spraying cleaning water to the dust collection electrode of the wet electric dust collector. When the cleaning is always performed, the acceleration of the corrosion in the dust collector is prevented by maintaining a high pH of the mist of the cleaning water. When the cleaning is performed intermittently however, the trapped dust is attached to the dust collector for a long time and the dust collector must operate in a harsh corrosion environment where the mist of the cleaning water has a pH value of 0.5.
The wet electric dust collector is also designed so that discharge electrodes are opposed to dust collection electrode plates to which dust or the like is attached. The dust collection electrode plates are arranged in a plane in a longitudinal direction. Upper and lower ends are connected to slung beams via a tightening member to sling and maintain the upper and lower ends. The dust collection electrodes and the slung beams are supported by a structure in which the dust collection electrodes and the slung beams include attachment holes through which bolts are inserted to tighten the upper and lower ends. Due to this supporting structure, spaces and holes are formed among the dust collection electrodes, the slung beams, and the supporting structure. If mist of the cleaning water having a low pH value enters the spaces or the holes, the corrosion is promoted. Thus, this must be prevented effectively. This type of wet electric dust collector for removing dust or the like that is attached to dust collection electrodes is disclosed in Patent Document 1 and Patent Document 2.    [Patent Document 1] Japanese Published Unexamined Patent Application No. H6-154652    [Patent Document 2] Japanese Published Unexamined Patent Application No. 2000-189836
It is an objective of the present invention to provide a structure for attaching a dust collection electrode of a wet electric dust collector according to which spaces and holes located among the dust collection electrodes, the slung beams, and the supporting structure as well as the characteristics of the materials are taken into consideration so that the structure is low-cost and resistant to all kinds of corrosions of entire face corrosion, space corrosion, and hole corrosion.